Brain Aneurysms: Silent but Often Dangerous

While many people know about strokes, most are less familiar with brain aneurysm, a condition that affects approximately 5 percent of U.S. adults. Aneurysms usually display no symptoms until they rupture and cause bleeding in the brain – an acute medical emergency. Let’s take a look at some of the facts on brain aneurysms.

What Is a Brain Aneurysm?

A brain aneurysm occurs when a blood vessel in the brain is weakened and becomes widened, or ballooned, into a small blood-filled pouch. As the aneurysm gets bigger, it places more pressure on the weakened area and can eventually burst. When a brain aneurysm bursts, it causes a stroke.

Estimates are that out of 100,000 people with brain aneurysms, 8 to 10 of them will suffer a rupture each year. About 40 percent of people who have a ruptured brain aneurysm do not survive. However, many people have smaller aneurysms that carry a low risk of breaking; in that case, the risk of surgically removing or treating the aneurysm outweighs the risk of it bursting.

How Do I Know if I Have a Brain Aneurysm?

Many brain aneurysms go undetected because the person usually doesn’t exhibit any symptoms unless the aneurysm pushes against surrounding brain structures. As a result, aneurysms are often found when an individual undergoes diagnostic testing for another health reason. A screening procedure such as a CT scan, MRI scan, or a CTA or MRA (CT or MRI angiograms) can detect the presence of brain aneurysms. If the aneurysm has ruptured, a spinal tap can also detect leaked blood in the spinal fluid.

Signs and symptoms that may indicate the presence of an aneurysm include:

vision impairment, such as a loss of vision, double vision, or difficulty with peripheral vision

unexplained eye pain

unexplained neck pain or stiff neck

loss of balance or coordination

localized headache

sudden weakness or numbness

difficulty speaking

However, because these symptoms can indicate so many other potential health conditions, a physician or medical team must rule out other possible causes.

The signs of a ruptured aneurysm are similar to those of a stroke. If you experience any of them, seek emergency medical attention immediately.

Who Is at Risk for a Brain Aneurysm?

The likelihood of developing a brain aneurysm increases as you get older; most aneurysms develop after the age of 40. Age aside, there are a few other factors that may heighten your risk for a brain aneurysm:

Family history: Research indicates that a family history of aneurysms could make some people more likely to develop one. Uncontrolled hypertension and high blood pressure have also been shown to increase risk.

Inherited disorders: People with certain inherited health defects or disorders also may be at a higher risk. Arecent study conducted by my colleagues at Cedars-Sinai, published earlier this year, found that people with a heart defect called bicuspid aortic valve were more likely to develop brain aneurysms, although more research is needed to confirm the relationship. Other inherited conditions, such as polycystic kidney disease, Ehlers-Danlos syndrome, and Marfan’s syndrome also appear to be associated with a higher risk of developing brain aneurysms.

Brain aneurysms are not always life-threatening, and many people who have them never experience a rupture. However, if you’re concerned that you may be at risk, talk with your physician about your worries and any symptoms you may have. He or she will take a look at your medical history and risk factors, and determine whether a screening is appropriate for you.